<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8"/>
    <title>Demo</title>
    <style>
      * { margin: auto 0; padding: 0; }
      #control {
        position: fixed; top: 0; right: 0; width: 300px;
        padding: 10px; box-sizing: border-box;
        background: white; opacity: 0.3; color: #666;
      }
      canvas {
        background: #ddd;
      }
    </style>
  </head>
  <body>
    <div id="control">
      <input type="checkbox" id="toggle" name="alpha" checked>
      <label for="alpha">Premultiply Alpha</label>
      <br/>
    </div>
    <canvas></canvas>
    <script type="module" src="./premultiply-alpha.js"></script>
  </body>
</html>
